An airship may be lighter than air or heavier than air. Certain airships may land, or be recovered, by dropping tethers. The tethers can be recovered by a ground crew. The ground crew may use a mechanical means such as a winch attached to the tether to assist recovery of the airship. The airship may be released, or launched, by gradually releasing a tether or by releasing multiple tethers.
Alternately, an airship may be recovered using a truck or vehicle mounted mast. A mast may be thought of as analogous to a pier used to moor a ship during shore-based operations, such as loading and unloading, or refueling. The mast may provide stability during ground operations such as loading, unloading, or refueling. The mast may be used in conjunction with one or more tethers which are analogous to mooring lines for a ship. As with recovery, release or launch is accomplished by gradually releasing one or more tethers. Releasing tethers acts to release or launch an airship, as releasing a mooring line launches a ship from a pier.
As with a waterborne ship, control of an airship during landing requires stability. A pier for a ship provides some additional stability. Similarly, a mast can provide only a degree of additional stability to an airship. Further increasing external control can provide increased stability while recovering the airship. Similar advantages may also be achieved in increased stability when the airship is released, or launched.
Airships are currently being developed that combine advantages of an aerodynamic shape with the cargo capacity, simplicity, and low operating costs. Uses for such airships include cargo transport, telecommunications platforms, surveillance, emergency response, advertising platforms, and tourism, among others. Airships may be slow and difficult to maneuver. Yet, it is desirable to provide capability that allows an airship to take off and land in a minimum amount of space and in a variety of locations.